1. Field of the Invention
This invention relates generally to switch structures, and more particularly, to a structure for a push button switch for use with instruments or machines particularly gaming machines.
2. Description of the Related Art
In a conventional gaming machine, as a slot machine, the rotation of a plurality of reels is stopped in response to the actuation of push button switch by a player. The winning a prize may be lost by a momentary delay in the operation of push button switch. Quickness in the operation of push button switch influences the results that can be achieved in the playing of the game.
It is a problem in commercial amusement centers that players will operate the gaming machines while foreign substances are on their hands. The foreign substances are present, for example, because the equipment is often operated while the players are eating or drinking. Thus, the operation of gaming machines, particularly the actuation of the push buttons thereof, with soiled hands results in contaminating material, such as food and beverage, entering into the into the gaps surrounding the actuation portion of the push button, and the push button itself being soiled. Food and beverage often are spilled directly on the push buttons on the gaming equipment. Insects are another cause of contamination of the push buttons of such machines. Insects easily enter and die in the gaps that surround the push button. These and other contaminating elements result in erratic operation of the button operation and loss of player control over the game.
When it is determined that the actuation of the push button cannot smoothly be performed or its operation adequately controlled by the operator, the push button unit must be removed from the gaming machine and cleaned. Such maintenance is expensive and troublesome, and results in significant machine down time. In addition, erratic or difficult operation of the gaming machine causes the players to lose interest in the game and the gaming machine itself, resulting in loss of clientele to the gaming establishment and low utilization efficiency for the equipment.
There is therefore, a need for a switch structure that is tolerant of contaminants. The prior art has thrust at this problem by decreasing the gap space surrounding the actuation portion of the push button of the switch structure. This switch structure prevents large sized contaminating materials from entering the decreased gap. However, small sized or liquid contaminating materials can penetrate into the gap, and the gap tends to become filled with the contaminating materials that disturb smooth operation of the push button switch.